AutoCodes – Generic – U1121

U1121 Code - Lost Communication With Electric Stability Program Module

Quick Answer

Several control units are applied to electronically controlled vehicles. Common causes include Faulty Electronic Stability Control (ESC) Module, Electronic Stability Control Module harness is open or shorted, Electronic Stability Control Module circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U1121 indicates Lost Communication With Electric Stability Program Module.
Common causes: Common causes include Faulty Electronic Stability Control (ESC) Module, Electronic Stability Control Module harness is open or shorted, Electronic Stability Control Module circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 23,234

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 21, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code U1121 Description

Several control units are applied to electronically controlled vehicles. These units perform each control with information from various sensors. Thus, sharing signal information from sensors is needed, so CAN communication type whose communication speed is high and insensitive to electrical noise by spark generation is adopted to controlling powertrain (TCM, ECM, CLUSTER, Electronic Stability Control (ESC), 4WD, SAS, EPS). CAN communication consists of CAN-BUS HIGH, CAN BUS LOW, and two 120 ohm resistance in the circuit. If the 4WD ECU doesn't get some ESC signals from the ESC module, it sets U1126.

OBDII Code U1121 - Lost Communication With Electric Stability Program Module - AutoCodes.com — U1121 Code - Lost Communication With Electric Stability Program Module

What does this mean?

What are the Possible Causes of the DTC U1121?

Faulty Electronic Stability Control (ESC) Module
Electronic Stability Control Module harness is open or shorted
Electronic Stability Control Module circuit poor electrical connection

How to Fix the DTC U1121?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1121 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the U1121 code?

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Information for Specific Makes

U1121 Hyundai — Lost Communication With Electric Stability Program Module
U1121 KIA — Lost Communication With Electric Stability Program Module

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U1121 Code

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Christian
Date: November 22, 2018 at 4:08 am

Que tal espero me alleden tengo un megane 2007 motor 2.0 y dejo de acelerar al pareser el cuerpo de aceleracion no esta travajando cuando piso el pedal ya rebise y le llega 5 v al conector y su tierra y al escanear me arrojo el codigo U1123 Y U112B espero me ayuden o me orientes si es nesesario remplaser el cuerpo de aceleracion gracias.

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